A Shadow of Doubt
by skygirl55
Summary: If Kate Beckett was ever sure of one thing, it was that never in a hundred lifetimes would she ever have expected this. (An AU version of Probable Cause)
1. Chapter 1

_If Kate Beckett was ever sure of one thing, it was that never in a hundred lifetimes would she ever have expected this. (An AU version of Probable Cause)_

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 _A/N: First of all I'd like to thank Lou (InkyCoffee) for being the prompt overlord and randomly tweeting out prompts that inspired this. Prompt is at the bottom of the page. It's super angsty and I'm not sorry. Enjoy!_

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If Kate Beckett was ever sure of one thing, it was that never in a hundred lifetimes would she ever have expected _this_.

Of course Richard Castle had been in her interrogation room before. Several times, as it happened, but not like this; never like this. This Richard Castle was a broken man: head bowed with chin to chest, hair mussed from raking his fingers through it so many times, collar of his shirt upturned and wrinkled, wrists shackled together on a chain looped through the table to the floor. This was the Richard Castle she thought she'd never see.

Thinking back a day earlier to when they found the gruesome scene in Tessa Horton's apartment, Kate's stomach churned and she felt nauseous. At the time, when she first saw the body, saw the peculiar ritualistic nature of it all, she had actually thought to herself, "It's a shame Castle isn't here; he'd like this one."

The thought surprised her slightly, because she hadn't thought about the writer in perhaps a week or more; that was a new record since his disappearance from the precinct and her life four months earlier. She had been trying not to think of him every hour of every day like she had for the prior one hundred and twenty-some days; she had been trying to move on, but after four years that was much easier said than done.

Four months earlier, after a bizarre case involving what appeared to be the undead, Castle had told her that case would be his last; he was ready to move on from shadowing her. To say that she had been stunned would have been an understatement. Shocked, horrified, angry, clawed-in-two seemed among the other descriptors she could use.

He'd been pulling away, she was aware of that, but she honestly thought they could get back to the place they once had been—the place on the path to more. He made the rounds saying goodbye, shook her hand and kissed her cheek like he had at the end of their very first case together, and then simply walked into the elevator and left her stunned and borderline traumatized behind.

All things considered, their parting had not been on poor terms. She might have even gone so far as to say they parted as friends. They had been in contact just a few times since—a random text here and there with limited meaning. He had also stopped by the Twelfth twice, though she missed him both times: once due to a day off, the second time due to being in interrogation.

Still, even after all those days, all that time with Dr. Burke talking about the situation practically ad nauseum, she could barely wrap her mind around his absence, the dissolution of their partnership. And now, to have him back like this…nothing made sense anymore.

Her world fell apart at the touch of a finger—quite literally. The fingerprint on the doorframe at their victim's apartment to be exact.

As with any crime scene, CSU examined every surface of the room in which the victim was found. In this case: the main living area of her own apartment. They checked for prints, DNA samples, hair—everything and anything that could help find witnesses or the killer him or herself. Unfortunately, most times the prints or DNA collected did not yield any matches. If they did, she and her team surely would not have been as busy as they always seemed to be, but it was simply a nature of their job.

The prints on the exterior of Tessa Horton's apartment matched immediately to one Richard Castle. It was an eight point match, so far from the most damning of matches. In fact, a halfway good lawyer (and they knew Castle would have an extremely good lawyer) could probably get a suspect off on such a low-by-standards matching. The fingerprint being on the outside of the door did make it seem almost reasonable. Perhaps Castle had paid Tessa—or her roommate—a visit over the prior week or so, which would certainly not be a crime. Still, being that it was Castle, it seemed odd.

Then, they interviewed Elle, Tessa's roommate, who described their victim's secret boyfriend as rich, handsome and generous—three adjectives that would easily fit the writer. Though, as Ryan was quick to point out, would also fit several hundred other men living in Manhattan. Kate agreed, and they returned to the apartment to search some more.

When the earring found in the couch lead them to the security camera footage from a high-end jewelry boutique Kate was excited; thrilled. Maybe having their victim's mystery man on film would not be as good as having his business card in her hand, but it was most certainly a step in the right direction. And then Kate saw the video.

As she had been hopelessly in love with him, Kate Beckett was incredibly familiar with all things Richard Castle. The way he moved, the way he walked, his mannerisms, and the way he looked from every angle. The man on the video paying over twelve thousand dollars for Tessa's earrings was so eerily identical to the mystery writer that Kate had to excuse herself from the room. For the first time since her rookie year as a cop she was certain a case was going to nauseate her to the point of vomiting.

She knew Castle was the man on the video. She knew it in her bones, but it didn't make sense.

Richard Castle was many, many things—some of them good, some of them not as good, but none of them a murderer. She knew in her heart of hearts that there was no way Castle would kill anyone let alone commit such a gruesome, twisted crime. It simply wasn't possible. From the looks on the faces reflecting back at her, her team felt similarly.

Bank records, more security cameras, and a few tears she tried her best to hide behind a curtain of hair later she found herself outside the door to Castle's loft. They presented him a warrant to search the premise, Ryan and Esposito held him aside, and Kate was certain the look of utter betrayal on his face as she walked past him and he pleaded out her name was one that would be burned into her mind forever. But she pressed on; put on her stoic face and did her job. She was there as her team found the matching bag, the rope inside and the bloody shirt. From that point forward she existed in a state of suspended disbelief.

This just could not be happening.

Yet, it most definitely was.

Straightening her shirt, Kate took a step back from the two-way mirror and prepared herself to enter the next room and interrogate her former partner, best friend and—well, she couldn't think about that right now. Right now Castle was just like any other suspect.

Except he wasn't. And everyone knew that.

Still, she turned, prepared to be as professional as she knew she could, but found her superior blocking her path. Gates gazed at her, her reading glasses held loosely in her left hand, and Kate could feel judgement pouring over her like a wave. She dipped her chin and moved to pass the woman but, as she did so, Gates said, "Don't go easy on him, Detective; I'll be watching." Kate said nothing in response, but moved swiftly from the room.

* * *

Kate had barely crested the edge of the threshold when she heard, "Beckett! Thank god!" come from the detained man. He did, indeed, sound like a man praising the heavens above and she couldn't say she was surprised; he had been secluded in Interrogation Room 1 for almost forty minutes by himself. Based on what she knew about him, she was certain he was in complete agony.

She didn't greet him as she normally wouldn't to any suspect seated in that chair. Instead, she entered the room with head held high, shoulders squared, and with a confident stride. She placed the folder of photos and other evidence down on the table before delicately pulling out the metal chair opposite the writer, being mindful so that the feet did not scrape stringently across the floor. Then, with hands clasped before her, she sat and took him in.

Castle's ice blue eyes, usually filed with such joy and jest, expressed his utter terror and confusion. Looking at him, looking at his face, his smile, the little crinkles at the side of his eyes, used to comfort her, but now everything about him stirred a sense of dread within her gut and she fought to keep herself from looking away. She moved her gaze from his eyes to his nose, mouth, cheeks, hair—everything that should have seemed quite normal, but was anything but.

How many nights had she spent dreaming about his lovely, ruggedly handsome face? Before he'd left the precinct the answer probably would have been: almost every. After his absence, it had been most assuredly every. She would dream about him, have dream conversations with him, dream fights with him…dream sex with him on occasion. She would wake up more hurt and confused than before, the gaping hole in her chest—the one from emotions not from a bullet slug—throbbing as she wondered why he had stopped loving her.

Castle telling her that he loved her was perhaps the strangest moment of Kate's life as it added to the barrage of shocked emotions her brain was progressing through while she lie on the grass in a graveyard bleeding out from the sniper's bullet to her heart. She had been stunned, confused, a little angry, but most of all relieved. He loved her. Someone—a wonderful, kind, incredible, miraculous man—loved her. Her—broken and battered, standoffish and sometimes too secluded for her own good. Her.

That moment was the one she clung to as she faded in and out. It was the one she thought about when the pain in her chest seared so deeply she wished for death just so it would end. It was the exact second she thought about for the next several days as she drifted in and out of her pain medication soaked haze. She would wake up whispering his name, praying she had the strength to return his sentiments and cursing herself when she concluded she did not.

If he loved her then—disastrous mess as she was—why didn't he love her months later when their partnership was stronger than ever—when they were closer than ever? What had changed and why?

Dr. Burke told her she was being unfair and he was right. Castle was a human being, just like she, and he was entitled to his own set of feelings, emotions and decisions. Sometimes there wasn't a concrete answer for everything, Dr. Burke had said, sometimes things just were what they were.

Kate Beckett could not accept that, for if she could she would not have been Kate Beckett. She needed to know the reason why—she always needed to know the why. Deep down in her molecular structure, every inch of every cell in her body needed to know why—for everything. Why did people do the things they did? Why had her mother been murdered? What caused people to turn so viciously on one another?

Finding the answer to the question why had been the reason she turned to Castle's books in the first place. They gave an explanation and a reason. They gave her the answers. So why couldn't he give them to her in real life?

There had to be a reason—there was always a reason. Was it something she had said? Something she had done? What flipped the switch? She had spent hours—days—of her life mentally reviewing their conversations and interactions, but she had yet to find a solid conclusion. That was when the more masochistic side of her brain began to speak up.

Maybe the reason was that he'd simply grown sick of her—sick of waiting for her to turn into the person he could be with. Sick of her not being normal—capable of letting go of her fears and having a regular, open, intimate relationship with him.

Dr. Burke had pointed out that perhaps she was expecting too much of Castle. Perhaps he had seemingly given up on something but in reality just took a step back not knowing what there really was to lose. She had not been direct with him. She had implied and danced around the issue—like she always danced around her true feelings. God forbid she tell anyone what was really going on beneath the many layers of the Beckett Onion.

She thought he knew; she thought he understood. Maybe that wasn't enough. Maybe he hadn't really understood, or thought he had but hadn't in the end. Maybe he was confused, uncertain and it had gone on too long without further clarification—nearly nine months since they'd halfway talked about it—and he had merely given up.

That was what she was trying to live with up until the point at which he tumbled back in to her life: this was her fault.

Dr. Burke also wisely pointed out that it was never too late. They hadn't even ended on poor terms. Picking up the phone and calling him would have been all too easy. She could also text and ask him to meet for a drink, for coffee. Then she could explain. She could ask questions. She could get closure.

Having an open, honest conversation? Right. When would that ever be her reality? It wasn't her style, but god, she wanted it to be. She wanted to know—even if it would hurt. Even if it would mean she'd never love again for the knowledge that she and she alone had driven away the one man who would have been her partner for always, her comfort, her one and done was almost too crushing a thought to bear.

She did, at least in theory, plan on having a conversation along those lines. That was to say she wanted to and hoped she'd have the strength when the time came. She was invited to the next Nikki Heat book release party and had every intention of going. She thought maybe they'd get to talking at the party and that would lead to coffee another time. They would take and maybe…maybe…

God, she was a coward when it came to her heart and she hated that, but she had tried with him, she had tried so hard that it left her sobbing in her bed more often than she would ever admit only to have it fall apart in the end.

But that was the way it was, wasn't it? Everything in her life seemed to fall apart eventually. Even this.

"Beckett, please say something. Please tell me you know I didn't do this."

"I know what the evidence says and it isn't good."

With that, she flipped open her file and studied it carefully. The writer continued to plead.

"Kate, I don't know what's going on here—honestly, I've never heard of this girl. Tessa? I don't know her; never met her. Don't even know what she looks like. But, Beckett, I swear to god-"

"Where were you two nights ago?"

He blinked at her, almost started. "Two nights ago?"

"Yes. Let's say…starting at seven all the way to midnight."

"At home—at my home. In the office. Trying to—trying to write." He said the task as though it were an inconvenient but necessary chore like scrubbing a toilet or cleaning up a mess on the floor.

"Can anyone confirm that?"

"Ah, no."

"Your mother? Your daughter?"

"Alexis doesn't live in the loft anymore."

Kate's gaze shot up to him and her stringent interrogator exterior slipped into one of concern until he explained, "She's staying in the dorms. First semester started already."

Oh right. That made sense. Nodding with relief, she asked, "And Martha?"

The writer shook his head. "She was out all night and you know my 'don't ask don't tell' policy."

"No delivery men, neighbors…no one can confirm you were home?" She questioned; he shook his head. Picking up a photo from her file she flipped it around so he could exam it properly and asked, "When did you meet Tessa Horton?"

"I haven't. As I said, I never met her; I don't know her."

"You were never at her apartment?"

"No."

She picked up another page in her file—a photo of the entrance to the crime scene—and flipped it around for him to see. "This is her apartment. Look again. Were you there?"

"No."

"Your fingerprints were."

"Where?"

She shrugged. "Everywhere. The door frame, the door knob, inside…" Okay, that last part was a lie, but she was trying to trip him up, provoke him.

"That's ridiculous I was never—frame. Framed! I'm being framed!" He proclaimed as though he had just solved the clue to the puzzle he'd been agonizing over for a lifetime. "Beckett that's it—the story that makes sense. I'm being frame. Someone got my prints somehow—I don't know how. One of those Mission Impossible like gloves when they shook my hand or something and then they—what's that?"

His voice when from excitable to barely above a whisper the second she put the third photo in front of him. It was a screen grab from the surveillance photo at the jewelry store showing him—or a man who was absolutely his carbon copy—purchasing Tessa's exorbitantly priced earrings. Kate lifted her right hand and tapped her index finger just above the photo. "That's you, isn't it?"

"Where is this from?"

Her tone slightly impatient she asked, "Is this you or not in the photo, Mr. Castle?"

Presumably at her sudden formality, the writer gazed up at her and responded in a clipped tone, "I don't know; where was it taken?"

"The jewelry store where these earrings were purchased," Kate said, adding yet another photo—this one of the discovered earring—to the pile.

"I've never seen those earrings."

Kate picked up another document—a photocopy of the cashier's check used to pay for the item in question. "This is the check you used-"

"I didn't!

"-to purchase these earrings."

"It's a cashier's check, Beckett; there's no evidence _I_ paid for the earrings."

Kate picked up yet another sheet of paper. "This is a statement of your account showing a withdrawal of this exact amount on the same day."

Castle snatched the paper from her grasp as best he could with his restricted hands. "You went through my financials?"

"The evidence-"

"Is wrong." He concluded for her. Castle dropped the sheet of his financial records back to the table before continuing. "Beckett come on. This is all smoke and mirrors—fabricated evidence. You know me. You know who I am. I didn't do this; I couldn't. Beckett. Tell me you know that. Tell me!"

Inside, she was screaming, crying, falling to her knees before him and promising she would fix this for him—for them—but on the outside she refused to register his pleas.

She knew he could never have done this. Barring a video of him actually committing the gruesome act she would still believe in his innocence. Even then, she'd struggle and wonder if he'd been under duress, if his family had been threatened—if there was even the smallest of reasons that could explain his actions. Richard Castle didn't hurt people; he made this world a better place.

Before she could respond verbally, a knock on the interrogation room door pulled Kate back to reality. She gave the writer one last look before pushing back her chair and walking towards the exit. Just as her fingers curled around the door handle she heard, "Please, Beckett; please believe me," and her heart broke all over again.

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 **Prompt: What if Probable Cause happened after C/B stopped working together after the Headhunters case.**


	2. Chapter 2

_A/N: i really cannot even begin to thank everyone for all your reviews/follows! They mean so much. I'm glad you guys are excited about this ficlet._

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"Sir, if you-"

"Detective." Gates stopped the younger woman's attempt at protest by raising both her hands as she exited the interrogation room. "It's out of my hands."

"No, it's not. It's not. We need to just take a step back and look at the whole picture. If we do that-"

"If we do that we will see exactly what we see now: Evidence that clearly indicates Richard Castle as our murderer." The captain's tone was tired and impatient and Kate couldn't blame her; it had been an exceedingly long day and she was operating on sheer determination—and coffee.

"But sir-"

"Enough. Detective. I'm calling the DA."

"Captain Gates please." Kate stopped the woman once more before she could walk away. By this point, her colleagues Ryan and Esposito had clustered around them. Kate clasped her hands tighter in front of her and lowered her voice. "Please I am begging you. You were here with us—my entire team—for almost a year and you had to have seen. You have to believe that Castle wouldn't do this; he wouldn't. We just need a little more time."

Gates expression appeared sterner, mind-blowing as that seemed, and she folded her arms over her chest. "I won't deny that Mr. Castle's descent into such violent criminal acts is surprising, but the evidence-"

"Can be wrong—misleading. Castle taught us that more than anyone."

"And this evidence, Detective?" Gates asked, gesturing towards the pile that had arrived on Kate's desk while she was doing the first round of interrogation.

CSU had finished processing the writer's apartment and they had not come up empty handed. While a search of his computer revealed that, just like the victim's computer, much of the hard drive had been wiped, they were able to recover via a USB storage device several dozen emails exchanged between Castle (using his personal Gmail account) and the victim. From the way they were worded, there was no question that Castle and Tessa were in an intimate relationship, one he was trying to hide from his family and possibly even another girlfriend.

Castle had left her. Castle had moved on. Castle had found someone else—possibly even more than one someone else. As a mark of just how strong her feelings were for him, this was the blow that hit the hardest. Kate wanted to run to the bathroom, lock herself in a stall, and cry for as long as she needed to, which, at that point, felt like it would be about several days. She, however, could not. She was forced to take in the painfully sympathetic looks from her colleagues and bounce back as quickly as she could from the gut-punch she had just received.

Perhaps even more damning than the emails that seemed to indicate motive was the other recovered file on the USB drive. It was a word document outlining how to create the perfect murder. Several of the bullet points corresponded so alarmingly to the murder of Tessa Horton that Kate actually got goosebumps while reading them. As an added insult, the document detailed the amusement that he, the killer, would feel as he watched the police bumble around his perfectly constructed crime scene and how they would never know he was the true killer.

With these items in hand, Gates had insisted that she would be the one taking over the questioning. As she was practically too stunned to move, Kate had not protested. She merely exchanged silently distraught looks with the boys and the three of them took their place behind the two-way glass to watch the most distressing interrogation she had ever seen.

Again and again Castle repeated that he was not dating Tessa, he had never met Tessa, he had never emailed Tessa, and he most assuredly was not hiding his relationship with Tessa from another girlfriend because he wasn't seeing anyone at that moment. While this comment did make Kate feel better, the lighter feeling didn't last. As Gate's questioning became more severe, he began begging for his former partner, asking the captain to ask her, ask anyone to provide a character witness. By the time Gates was done, the writer was near the point of tears.

"Like I said," Kate continued, "the evidence isn't always what it seems. There's more to this story and we need to look into it."

Gates shook her head. "And if this was any other person? Any other suspect? You'd have already thrown him into lockup and speed dialed the DA. Wouldn't you have, Detective?"

"But it's not another suspect." Ryan chimed in. "Castle was part of our team."

"But he hasn't been for months! He could have been up to anything in that time." The captain rationalized.

Ryan shook his head, steadfast. "This isn't like him; this isn't Castle. He says he thinks he's being framed and we should look into it; we owe him that."

As she remained unconvinced, Gates turned to the final member of the team. "You're being suspiciously silent, Detective Esposito."

The dark skinned man looked to each of his colleagues before turning to the captain and stating matter-of-factly, "Well, it's like you say, the evidence fits. It's practically an open and shut case. Video, fingerprints, these letters imply motive…"

Kate's jaw dropped an inch and her skin broke out with a cold sweat from horror. What was he doing? Why would he throw Castle under the bus? After all their years together. She was about ready to pounce on him when he continued.

"…except one thing: everyone we've spoken to so far has described our killer as cold, calculating unemotional. That's not Richard Castle."

Kate almost smiled. It was three against one; surely Gates would see that they deserved more time.

"You don't think he could have hidden a darker side from you? From his family? He wouldn't be the first."

Esposito shook his head. "To be honest: no. He's not that smart—he's not that smooth."

"Besides," Ryan chimed in again, "the motive doesn't fit – he doesn't have a girlfriend or a wife."

"That we know about…"

Ryan walked over to the murder board and pointed to their evidence. "But think about it – everything fits, but only by about ninety percent. Yes, Castle is in the security videos, but he never shows his face to the camera at the jewelry store or the bank, even though it would be natural to do so. He wipes down the prints inside the apartment, but not around the door? He knows our procedure; he knows we check everything."

Feeding off his excellent points, Kate once again stepped in front of her superior. "Sir, it doesn't make sense—it doesn't add up. We need more time."

For almost a solid minute the captain looked between the murder board and her detectives. Finally, she shook her head and opened her arms, defeated. "I'll give you twenty-four hours and not a second longer. That's all you get. And," she added threateningly, "you'd better hope you come up with something irrefutable."

After thanking Gates, Kate waited until she walked away before turning to her team. "We need something—anything—that makes even half as much sense as Castle. We need to cast a shadow of doubt on this so the DA doesn't want to prosecute."

Ryan nodded in agreement. "But where do we begin?"

Kate gazed at the evidence piled on their desks, to the murder board, and then back to her team, setting her expression. Sometimes, when a case ran them into a dead end, there was nothing else to do but start back at the beginning. It felt like they'd gone over everything, but maybe once more, with fresh eyes, they'd find the piece they needed. They'd review the CSU reports, the surveillance video, look at traffic camera footage, and even go back to speak with Castle's family if they needed to (though, given how distraught Martha and Alexis had been during their initial conversation, Kate wanted to avoid upsetting them further if possible). "We start where we always do: back at the beginning."

* * *

The precinct was colder in the middle of the night; eerier. Or perhaps it was just her; she had been wrenched from REM sleep after laying down what felt like only moments earlier. At two a.m. she was fading. She'd sent the boys home an hour earlier but it was her partner in that holding cell, which meant if she had to free him on her own, she would. She had settled on to the break room couch, fallen asleep almost instantly and only woken when LT shook her shoulder and told her she needed to get down to holding—urgently. Apparently, Castle was hysterical.

Shivering as she descended the stairs, Kate could only imagine what sort of incident had shaken the writer. Truly, she had no idea, but she imagined a very creative story was about to come her way. Her wildest imagination could never have predicted the tale he spluttered out.

Jerry Tyson, the man formerly known as 3XK, the Triple Killer, had paid the writer a visit in his holding cell. He'd issued various threats and promises of painful drawn-out deaths—his usual greetings. According to the writer, during their tete-a-tete the fugitive had more or less confessed to murdering Tessa Horton, breaking into the Castle loft, planting evidence, and conspiring the whole thing as retribution for Castle foiling his plans to escape without ever being caught a year prior.

The story was impressive, even for a career writer, Kate had to admit. Unfortunately for Castle, it simply appeared to be another fabrication. The security footage at the precinct was checked immediately for tampering. They found none nor did they find Tyson. The head of night security accused Castle of hallucinating, dreaming, but the writer remained adamant that Tyson was as real as his threats.

"His going to kill me, Kate." Castle gazed directly at her, griping the bars of his cell until his knuckles were white. "He said when I get transferred someone will be waiting—someone he's hired—and I won't make it out."

The concept of her partner being so vulnerable caused a chill to go down Kate's spine. She couldn't protect him in the tombs; no one could. Whether or not Jerry Tyson came to visit him was no longer in question. Whether or not he committed a heinous crime or was being question was no longer relevant. If he left the twelfth precinct he would not survive and that was the next boost of motivation Kate needed to continue.

After the supervising officer in lockup told Castle he needed to get some sleep, Kate and the others left the writer alone in his cell. While they went back to their posts, Kate returned to the tech room to review the video footage one more time for herself. Of course, nothing new was seen, which meant she needed to once again speak to the only man who could tell her what happened. On her way down to lockup she texted both Ryan and Esposito telling them who was behind the murder and that they needed to get back to the precinct ASAP.

Kate paused just outside the door to lockup. For the first time in over twenty-four hours her shoulder's felt less heavy, her chest less tight. This was it—the break they needed. It may not have come in the form she anticipated, or even in the most useful of ways (damn that savvy psychopath for removing every inch of himself from the video feed somehow), but it was a start. It was the sliver of hope on which they would build their case.

Upon entering, Kate signaled to the overnight guard to buzz her through. He did so and, fortunately, Castle was lockup's only resident that night. He had been sitting with his head cradled in his hands on the small cot in his cell, but when he heard the door buzz he looked up. On seeing his visitor, he pushed himself off the cot and over to the edge of the bars.

"Beckett! Oh god Beckett you have to believe me! I know how it sounds. Everyone thinks I'm crazy. All this evidence against me of course I'd make something up but I swear to god I'm not making it up! I'm not!"

Kate remained silent, curious as to where his pleas would lead. During the duration of their nearly four year partnership she had learned very quickly to tell when he was fibbing. She was pleased to say those events were few and far between and he was most assuredly not lying now. As he would have said, the story was finally beginning to make sense.

"Please. Please Kate—you just have to believe me. I am begging you. You know me—you know the real me—that I couldn't have done this. Think about all the years we spent as partners. We worked case after case…everything we went through…I know you never felt the same as I did but-"

"What does that mean?" She cut him off quickly. Never felt the same…? What did that refer to?

He blinked almost startled that his monologue had been interrupted. "Nothing."

She took a step closer to his cell. "No, Castle—what?"

"You…" He continued, though very softly "You didn't have feelings for me other than partnership."

Kate sucked in a breath so deeply it was audible. Oh god, is that what he thought? What he truly thought? But they had…she was sure that he…and there had definitely been moments where… Oh god. "Is that what you think?" She responded, barely above a whisper.

"I know." He corrected.

Her brow rose. Seeing as she had never confirmed as much to him, she failed to see how he could sound so certain. "How?"

"I heard you."

"When?"

"In interrogation—months ago. You said…you said you remembered your shooting, which means that you knew. I told you how I felt and you knew but you said nothing so-"

"Oh god Castle…" Kate brought her hands up to cover her face as she began to pace the small area in front of his cell. Oh no. No, no, no. Shit. When had that been? What case was that? The man who claimed he didn't remember something traumatic… it was the prior spring. Just before…oh god, just before Castle started acting strangely. It all made sense!

Castle must have—oh god—he must have thought that by her not acknowledging his beautiful sentiments despite having heard them meant that she didn't feel the same. That she was…what? Embarrassed? Didn't want to make things awkward? And that had to have been why he left—not because he didn't feel the same, but because she didn't. Well, because he thought she didn't.

"What? Kate?" he added after she had been silent for several moments.

She turned back to him and he looked—oh, so hopeful. So sweet. Like he was about to receive the world's greatest present, but wasn't quite sure if he was the true recipient yet. But—oh no. This was wrong. They were separated by bars. Castle was about to be charged with capital murder. "No." She told him. "No—we cannot deal with that now."

"Kate." He began, insistent as he stepped up to the bars of his cell and gripped on to them. Sticking his face against them so tightly that his nose poked through, he continued. "Did you not hear what I said? I'm not going to survive the tombs. Now is all I've got."

Well…he did have a point. She had every intention of clearing his name, but if she could not then… she didn't want to miss another opportunity, terrifying as it was. Tentatively, she glanced towards the night guard, but he was thankfully oblivious. Lowering her voice, she stepped right up to the cell door and said, "I told you I needed time Castle."

His eyes darted back and forth and she could almost hear the wheels of his mind whirring to life. "Yeah but I thought…" He swallowed hard and leaned away from the bars. Now sounding slightly ill, he said, "Kate did…did you feel the same? Kate please tell me I didn't make the biggest mistake of my life by walking away from you…again."

She shook her head. It was certainly not the biggest mistake of his life. It was a mistake that, in all likelihood, was fixable—but not while he was behind bars. "We have to get you out of that jail cell, Castle then we'll deal with that." Shaking her head to clear her mind of thoughts of Castle loving her, Castle waiting to be with her, Kate then took a deep breath and focused. "Now tell me again what Tyson said—start from the beginning."

The writer swallowed hard again, only this time he leaned forward so his nose poked through the bars again. "You…believe me?"

He sounded so…afraid. Afraid to be happy. Afraid to think something positive. Kate simply couldn't help herself. She lifted her left hand and placed it atop his right, wrapping her fingers around it the best she could. Offering a smile wider than she could have imagined in that moment, she said, "I've believed in you for longer than you know, Richard Castle."

For the first time since being arrested, Castle smiled too.

* * *

 _A/N: There will be one more part._


	3. Chapter 3

It wasn't supposed to be like this.

Kate Beckett's life wasn't supposed to be like this—not again. Not again.

Barely two minutes had passed since Castle stepped into the elevator with the two uniforms escorting him to central booking and she had already begun to feel his absence like weighted barbell balanced atop her shoulders. When he left before she was hurt and confused, but that sliver of hope remained with in her—the hope that somehow, someway they'd find their way back to each other. Now, that hope was non-existent. Instead, the only emotion inside her was dread.

How long would it take for Tyson's contact to find and eliminate Castle? She imagined the psychopath would want it done as quickly as possible. An hour? Two hours? How long until she heard the official word that Castle's body had been found in amongst murderers, rapists, and other criminals? How long until what she feared to be her only chance at a happy ending evaporated into nothing?

A single tear escaped the corner of Kate's left eye and she shook her head causing her hair to curtain down across her cheek and hide this display of emotion from her colleagues. She saw it on their faces as the cuffed writer was led across the bullpen; Ryan and Esposito were upset at the prospect of losing their friend, too. They were still working the case, at their desks making phone calls, reviewing documents. She should have been doing the same, but as hopelessness washed over her again, all Kate could think was, "What's the point?"

Once again, she had failed to solve one of the most important cases of her life, only this time was far worse than the other. If she never solved her mother's case it would be a grave disappointment and something she would think about to her dying day, but her mother couldn't die again. However, Castle would be killed as a direct result of her inability to find enough evidence to clear him.

Rationally she knew that the person responsible for Castle's death would be Jerry Tyson and whomever he hired to carry out the hit, but Kate's brain did not have patience for rationality at that moment. Inside her mind, one sentence was on repeat. _He's going to die and I can't stop it_. The notion made it feel as though a tourniquet was around her chest squeezing tighter and tighter until all her ribs broke and all her other organs were crushed along with them.

Kate was so distracted by berating herself internally she failed to notice the comeuppance by the elevators until Gates called out her name. Somewhat startled, she jumped to her feet while simultaneously rubbing her cheeks with her fingertips, trying to clear off any tear tracks that remained, "Yes, Sir?"

The captain thumbed towards the two uniforms standing behind her. "These men are here to escort Mr. Castle to central booking."

Kate blinked. "But…he's already gone."

Gates clasped her hands in front of her and took a step forward. "Yes, Detective; I'm aware of that," she said in a tone that was anything but patient.

"So…dispatch sent the order through twice?" She guessed. It certainly would not have been the first time such an incident happened.

Gates evidently had another theory because she called out, "Can anyone verify the badge numbers of those two alleged transport officers?"

Shit. Oh Shit. Kate had not even thought about the possibility that Castle had been—oh god.

So that was how he was going to do it! Killing Castle inside the tombs would be difficult but certainly not impossible. With a man of Tyson's intelligence and level of deviousness she imagined it would be tricky but well within his scope of abilities. However, more than one point existed for the plan to go awry, and Tyson had made it plain how strongly he hated when his plans were interfered with, thus he had sent fake officers to take Castle from them and they would be the ones responsible for the writer's demise.

Kate's stomach flipped in her gut and she brought up her hand to cover her face. God, oh god. He might have already been dead!

Immediately she began to regret her actions from twenty minutes prior. She had requested to be the one to cuff Castle for his transfer just so she could be close to him again, so she could touch him one last time. She expressed how sorry she was but he refused her apology making sure she knew he didn't blame her in any way and she wasn't to worry about him. He gazed at her with such tenderness and kindness as she spoke, and the best she could manage to was to linger her fingertips against his wrist for an extra few seconds. She should have pulled him close and hugged him—kissed him. Gates probably would have suspended her, but what would that have mattered? Nothing mattered anymore.

"Security cameras show them leaving the underground garage. We ran the plates and it shows that it was sold at auction two months ago." Ryan informed the time. Kate fought to keep from cursing aloud. "I'm looking in to the purchase now, but it was all cash—no way to tie to Tyson."

"You know there is another possibility." Gates chimed in and the detectives looked at her, curious. "That Mr. Castle orchestrated this himself. He's got endless resources and knows our procedures in and out; it wouldn't have been difficult."

Esposito scoffed. "I think you're giving him too much credit, Captain."

"I disagree," Gates said. "And if he was guilty-"

"But he wasn't." Ryan interjected.

As the trio continued to argue, Kate took a step back, her brain whirring to life. Just as she cuffed him, Castle had made a comment about the very first time she had arrested and cuffed him—four years earlier in the New York Public Library. _What I wouldn't give to be back there now_ , he had said. At the time, she'd been too distraught to offer anything more than a soft, "Yeah," but Gates's proposal had brought the incident into question.

What if…what if… oh god.

It was a long shot—she knew that—but there was a chance and if there was any chance at all she had to follow through. Without even speaking to the members of her team, Kate turned on her heel, rushed back to her desk to grab her jacket and keys, and then took off towards the elevator. She heard both Ryan and Esposito call out her name questioningly, but she ignored them. She had no time to waste trying to explain a scenario that might not even be true, but god, she wanted it to be true—she _needed_ it to be.

* * *

Kate had no idea how big the New York Public Library was until she began to search it. She knew if the writer had been with her on her journey he would have been sprouting off facts about square footage, how many titles it contained and how large that was compared to other public libraries in the country. She would have looked at him annoyed, but really would have been impressed as always at the breadth of his knowledge. Now, the expansive space merely gave her anxiety as she checked each floor, every section, with no avail.

Finally, as she was descending the staircase she caught a glimpse of a figure she had not seen during her initial sweep of the second floor. Her heart leapt up into her throat and she leaned over the railing to study the man hunched at a table tucked among the stacks. He wore a blue unmarked baseball cap, which certainly was a new addition, but the button-down he wore appeared to be the same plumb shade Castle was arrested in.

Kate stepped down one step to get a better view and the man looked towards her. He caught her gaze and the moment blue met brown she felt tears pricking her eyes once more. Immediately, she was overwhelmed with relief but also nearly overcome with confusion. What the hell was he doing?

Though she wanted to leap down the stairs and take three at a time, Kate managed a calm pace so as not to rouse attention. She weaved her way through the stacks to the table at which the writer sat. When she reached him he stood and they stared at each other silently for the span of three seconds before she practically jumped forward and locked her arms around his neck. "Thank god you're all right." She exhaled into his neck.

"Sorry if I scared you." He muttered back, squeezing her just as tight as she was squeezing him. "There was no way I could tell you and I couldn't risk contacting you now that I'm out."

"Castle, oh my god." She pushed back from their embrace and shook her head as she stared up at him. "How did you-"

"Trust me—the less you know the better." He explained.

Clearly, the detective would not stand for such a vague answer, but before she could open her mouth to inquire further, her phone rang. She jumped as she had forgotten to put it on silent mode before entering the quiet space. She swiftly pulled the device from her pocket and moved to turn down the volume when she saw the caller was Esposito and, hoping there had been a break in the case, she answered it as softly as she could.

"Where the hell are you?" the male detective demanded of her, not bothering with pleasantries.

"Uh." Kate's eye flicked up towards her companion. "Following a lead," she said though she knew her tone did not sound convincing.

"Well you'd better get your ass back here ASAP. Gates is going through the roof! The DA is now convinced Castle orchestrated this escape himself and has put out an APB on him."

"I see."

"And we still don't know if—" Esposito cut off his speech mid-sentence, was silent for five seconds and then asked, "You're with him, aren't you?"

Cracking the smallest of smiles Kate said, "I have no idea what you're talking about." Possibly picking up on her lighter tone, the writer smiled as well.

"I'm sure. Well the DA is out for blood so you better tell your boy to keep his head down."

"Will do. In the meantime keep investigating—we've got to find Tyson's connection to all this."

"Ten-four."

Kate pulled the phone from her ear, pressed the End Call button and then stared up at her partner once more.

"Am I in trouble?" he asked with a small amount of amusement.

"Extremely and you'll be in more as soon as every NYPD officer starts their manhunt for you. The boys are going to keep searching for clues to tie Tyson to this, but we need a plan."

"Ah!" he said, holding up his right index finger. "I might have something on that."

She arched a skeptical eyebrow in his direction. "Is this a realistic idea or one of Richard Castle's wild theories?"

He continued to gaze at her. "I thought you liked my wild theories, Detective?"

"Only when your life isn't in danger."

He bobbed his head. "Fair enough, but this is a good idea. A very good idea. An idea that will make you think I'm brilliant."

Kate felt tingles form at the base of her neck at the way Castle spoke the last word in his statement. His breath brushed across her cheek and she found herself leaning into him. He was so close—so very close—and there weren't bars between them now. She could so easily give in to what she wanted and just—

"Excuse me!" The sharp hiss of a library volunteer pulled Kate's mind back to reality. "This is a _library_ —you need to keep your voices down!"

"I'm sorry." Kate told the women as quietly as she could. "I promise we're leaving right now." The stern-faced woman walked away and Castle and Beckett exchanged glanced before she nodded towards the stairs. "Let's get out of here before anyone else sees us. You can tell me about your brilliant idea on the way."

He grinned and, without hesitation, grabbed her hand with his. "C'mon partner; you're gonna love it!"

* * *

"It's over, Castle."

"Hmm?"

Kate glanced over at her passenger as they made the drive back towards southern Manhattan. Though it was dark and she could hardly see the finer details of her face, she could still feel his body pulsating with stress and tension. "It's over." She repeated both for his benefit and her own.

Though the statement was true, she still found it hard to believe especially since, in the end, the reveal had not been nearly as shocking and twisting as she would have thought Jerry Tyson capable of. Castle's hunch that Tyson had hired an actor to play his doppelganger had paid off in spades. Once they located the man hired to do the bank withdrawal and purchase the earrings as "Richard Castle" it was barely a hop, skip and jump to the warehouse in which Tyson had apparently plotted his evil plan. Surveillance photos, schematics of both Tessa Horton's and Castle's apartment, and even specs about the precinct's security cameras easily absolved the writer of all guilt.

When Gates announced that Castle was cleared of all charges—including escaping police custody—Kate fought the urge to celebrate. Just twenty-four hours earlier she feared his life would soon be at an end and now he—they—had been given a second chance. Still, with her tendency to have a dark cloud over any happy moments of her life, Kate remained hesitant especially with the normally jovial writer not celebrating beside her.

He looked over at her and, when their eyes met, she could see how dark his gaze was. "It was too easy—far too easy."

She sighed and eased their vehicle to a stop in front of a raising drawbridge. "It wasn't easy—we got lucky, I'll admit that, but we needed a bit of luck, didn't we? Tyson screwed up and-"

"That's just it." Castle interrupted. "Tyson doesn't screw up—he's too smart for that. He wanted a way to make a clean escape and-"

Castle's observation was cut off by the squealing of tires and the crunching impact of a vehicle plowing into the back of Beckett's cruiser. Despite her foot on the break, the car lurched forward and began steadily moving towards the space in the bridge where the road was missing. Her fingers gripping the wheel and her foot pressing the brake pedal into the floor, Kate glanced in her rear view mirror and growled at the sight.

"It's Tyson."

"No shit!" Castle responded, craning his head to see behind them. A moment later he gasped. "Gun—he has a gun."

"Then get down!"

Her heart thundering in her chest, Kate slouched down as low as she could so her head was protected by the back of the seat. She flinched when the first bullet ripped through the rear window. Taking but a millisecond to weigh her next course of action, Kate wrenched the steering wheel to the left, turning the car into the edge of the bridge. When it crunched against the railing, she let out a breath of relief; at least they weren't going into the water. She quickly glanced at the ducking man beside her and said, "Stay in the car," before pulling her gun from its holster and clambering out onto the bridge.

As Tyson fired at them, Kate fired back in rapid succession, squeezing out at least ten bullets before she saw the shooter drop back in his vehicle. Not convinced her shot was fatal, but hoping he was at least significantly wounded, Kate approached the car. Just as she was reaching out for the door handle, the door popped open and smacked her hard, knocking her off balance and causing her to fall.

Kate cursed as her gun skidded away from her and Tyson's hand wrapped around her neck. He hauled her to her feet and she choked, spluttered, and clawed at his arm, trying to get him to release her, but it was no use; his fury made his grip iron-strong.

"Hey Castle! C'mere Castle!" Tyson called out, tauntingly. He pressed his gun into Kate's side just at the bottom of her rib cage and she grunted out in pain. "C'mon Castle. You can't save her, but I want you to watch—I want you to watch and see as the life drains out of her knowing that I've been in control all along."

As he spoke, Tyson moved forward with Kate still in his grip. She continued to claw, but her nails were worthless against the sleeve of his jacket. When they reached the passenger side of the cruiser, Tyson slowed his walk. "C'mon Castle—you don't want your friend to die without you now." Just as they reached the edge of the passenger door, Tyson moved his weapon from Kate's gut to be pointed out in front of him, obviously meaning to aim it towards Castle, but before Kate got close enough to look inside the vehicle, she heard a voice from behind them.

"She's not my friend; she's the woman I love."

Kate heard the gunshot just as Tyson whipped towards the back of the vehicle where the writer stood. When the bullet connected with Tyson's shoulder, his grip loosened and Kate slid out of it, dropping to her knees on the ground. The bullets continued to fly, but she stayed low, looking up just in time to see Tyson stumble backwards off the edge of the bridge. By the time her brain registered what had happened, Castle was at her side, scooping her under the armpit and hauling her to her feet.

"Kate—Kate! Are you okay? Are you hurt?"

"'m fine, Castle," she said, her eyes never leaving the last spot Tyson had been. She cautiously peered over the edge of the bridge and saw ripples in the water below; she shivered involuntarily. Well, he definitely wasn't coming back from that.

Turning back to her partner, Kate saw he wore an extremely guilty expression. "I'm so sorry, Beckett."

She shook her head. "This isn't your fault."

"But you could have been hurt. You could have…without knowing…" He shook his head and brought his hand up to his face, only then realizing he still held the gun. Carefully, he tossed it to the ground and stepped up to Kate. "I almost lost you again and I know you said you wanted to talk later, but this can't wait.

"Back in May I ended our partnership because I felt foolish. I thought I was following you around waiting for something only to discover you didn't feel the same, so I felt like an idiot. I realize now I was mistaken and I'm sorry for jumping to conclusions instead of confronting you about it, but you need to know that my feelings haven't changed. I…I spent the past few months thinking I could make myself get over you, but I can't—I never could because I-"

In one swift move, Kate stepped forward and brought her lips against his, cutting off his romantic confession. The writer hummed softly against her mouth before wrapping his arms around her, pulling her closer, and kissing her like she'd wanted him to kiss her for years. Unfortunately, that was also the moment that the sound of approaching sirens hit Kate's ears so she pulled back and rested her hand gently against his cheek as she spoke to him.

"Castle, I feel the same."

His eyes lit with recognition. "You...do?"

She nodded and then added carefully, "But Castle I don't want to dive in to anything. I...that's why I told you I needed time. It's hard for me to be completely open so…" She paused and gazed around the disaster area that was once a bridge. "Let's clean this mess up and then we can talk about us okay?"

Studying her face, he nodded. "We can...go to dinner?"

A smile creeping across her face she nodded. "I'd like that."

"Then," he said, giving her waist one final squeeze as the cruisers pulled up on the bridge around them, "It's a date."

* * *

 _A/N: Thank you to everyone for your reviews and follows! I really appreciate them!_

 _Also thanks to Lou for the prompt/inspiration - hope it lived up to your expectations!_

"Murphy's Law" _is coming next Saturday! Until then... :)_


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